They were rescued at 02:00 local time on Sunday and flown to University Medical Center in Las Vegas, Nevada, a statement said.

Witnesses told local reporters they had seen survivors running away from the crash site and shouting.

The youngest of the victims, Ms Dobson, worked as a veterinary receptionist for Vets 4 Pets in Worthing, West Sussex.

In her profile on the practice’s website, she described her love for animals, as well as her dream of becoming a veterinary nurse.

“I also love to travel the world and explore what is out there beyond good old Worthing,” she said.

Gabby Hart, a local news reporter for the station KSNV, said it had taken more than eight hours for the survivors to be removed from the site because of the terrain and high winds.

She told BBC Radio 5 Live: “We are told by witnesses and also by rescuers that people trying to help once they saw this accident happen, they couldn’t get down to the helicopter quick enough.

“They [the survivors] had to receive care there on site until emergency crews were able to remove them from the scene.”

The chief of the local Hualapai Police, Francis Bradley, called the incident “very tragic”.

He added: “Yesterday, we were hampered by severe weather conditions [and] we had gusts up to 50mph [80kmph].”

He said the terrain around the crash site was also “extremely rugged”.

In a statement, Brenda Halvorson, the chief executive of the helicopter company involved – Papillon Airways – said the company extended its heartfelt sympathy to the families of the dead and injured.

On its website, Papillon calls itself “the world’s largest aerial sightseeing company” and says it flies more than 600,000 people a year.

The Grand Canyon, which is more than 1.6km (one mile) deep, is one of the most visited tourist attractions in the US.

A UK Foreign Office spokesperson said: “We are providing support to the families of six British visitors involved in a helicopter accident at the Grand Canyon on 10 February, and we are in close contact with the US emergency services.”